- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Fri, 16 Feb 2007 11:01:22 +0000
- To: Ian MacLarty <iml@missioncriticalit.com>
- CC: www-rdf-rules@w3.org
Ian MacLarty wrote: > Now, back to the issue at hand. For me, having rdf:nil a member of > AtomList as it stands is problematic, since it means that in all models > rdf:nil must have values for the rdf:first and rdf:rest properties, > because of the cardinality restrictions imposed by AtomList. Checks .. yes, you are quite right that definition appears broken. I clearly wasn't very awake yesterday when I replied and had thought they were just maxCardinality constraints :-( > If AtomList were renamed to "NonEmptyAtomList" and AtomList was instead > defined as the union of NonEmptyAtomList and the singleton set > containing rdf:nil, then I believe the problem would go away. Agreed. Another common idiom is to omit the cardinality constraints or reduce them to maxCardinality. In that case having rdf:nil in the list class is not a problem. Though that is a less thorough modelling approach than the NonEmptyXList/XList approach. Hopefully there will be someone on this list involved with SWRL and able to comment on what the process might be for errata for the SWRL documents. Dave
Received on Friday, 16 February 2007 11:01:44 UTC